中文摘要：

目的 ：探讨共济失调毛细血管扩张突变（ataxia-telangiectasia mutated,ATM）基因沉默对人三阴性乳腺癌MDA-MB-231细胞增殖、迁移和侵袭的影响。方法 ：将携带ATM-sh RNA及其阴性对照序列（作为阴性对照组）的重组慢病毒载体分别感染人三阴性乳腺癌MDA-MB-231细胞,获得ATM基因稳定沉默及其对照细胞株;同时,设置未经病毒感染的空白对照组细胞。经嘌呤霉素筛选后,荧光显微镜下观察各组细胞的感染效率,并采用实时荧光定量PCR和蛋白质印迹法分别检测ATM mRNA及蛋白的表达水平。采用MTT法、FCM法、细胞划痕愈合实验和Transwell小室实验分别检测ATM基因沉默对MDA-MB-231细胞增殖、周期分布、迁移和侵袭能力的影响。结果：成功构建了稳定沉默ATM基因的人三阴性乳腺癌MDA-MB-231细胞株。与空白对照组和阴性对照组相比,ATM基因沉默组细胞的增殖能力和细胞周期分布均无明显变化（P值均〉0.05）,但细胞迁移和侵袭能力均明显减弱（P值均〈0.05）。结论：在人三阴性乳腺癌MDA-MB-231细胞中,ATM表达下调可明显抑制细胞的迁移和侵袭。

英文摘要：

Objective： To investigate the effects of ataxia-telangiectasia mutated（ATM） gene-silencing on the proliferation, migration and invasion of human triple-negative breast cancer MDA-MB-231 cells. Methods： The recombinant lentiviral vectors with ATM gene-targetedspecific sh RNA or the negative control sequence（as the negative control group） were infected into the human triple-negative breast cancer MDA-MB-231 cells to obtain the ATM gene-silencing cells. At the same time, the uninfected MDA-MB-231 cells was used as the blank control group. After screening by puromycin, the infection efficiency of each group was observed under a fluorescence microscope. The expressions of ATM mRNA and protein in MDA-MB-231 cells in the three groups were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The effects of ATM gene-silencing on proliferation, cycle distribution, migration and invasion of MDA-MB-231 cells were analyzed by MTT method, FCM, cell wound healing assay and Transwell assays, respectively.Results： The human triple-negative breast cancer MDA-MB-231 cells with stable ATM genesilencing were established successfully. Compared with the blank control and negative control groups, the proliferation and cell cycle distribution of MDA-MB-231 cells in ATM gene-silencing group had no significant change（all P〈0.05）, but the migration and invasion abilities of MDA-MB-231 cells in ATM gene-silencing group were decreased significantly（all P〈0.05）.Conclusion： The down-regulation of ATM gene expression can significantly inhibit the migration and invasion of human triple-negative breast cancer MDA-MB-231 cells.